virtual office address required

I require a virtual office address anywhere from the CBD to Sutherland. My requirements are:
- to nominate the address as my official business address
- mail delivery [for me to collect]
- a place to mount a small plaque [20 x 12 cm] in the foyer, front window etc [its a legal requirement in my industry]
- i don't need anything else as I have all my own communications facilities, home office, car office etc
- i might need an occasional short meeting there, in the foyer or empty desk is OK, not important. Happy to pay per hour used.
- visitor car parking would be great, to make it easy to run in and pick up my mail, but not essential.

I am what you might call a virtual real estate agent. Servcorp and the like have these kind of facilities, but I would like an arrangement with an allied industry, in a smaller office but that is not essential. Open to all thoughts.

Thanks, Michael.